There is little literature on Cocamidopropylamine Oxide and in an initial safety assessment, the Cosmetic Ingredient Review (CIR) Panel determined that there was insufficient data available to support the safety of this ingredient in cosmetic products, however, more recent data (2008), show that Cocamidopropylamine Oxide has low toxicity in animals and in vitro. Although there are no available data on carcinogenicity, the available genotoxicity data, combined with the absence of any structural alerts, do not suggest any carcinogenic potential. The Panel noted the absence of data on reproductive and developmental toxicity. As this ingredient has a highly polarised molecular structure, the Panel considered that it would, at best, be slowly absorbed. Given that most uses and the highest use concentration is 4% and is found in products intended to be rinsed off, the Panel determined that the available data suggest that Cocamidopropylamine Oxide is safe when used in products intended to be rinsed off. Although skin penetration may be slow and there is dermal absorption, data on reproductive and dermal developmental toxicity may be needed (1).

This other study focuses on the case of product-induced dermatitis (2).

Other studies:

Uter W, Werfel T, White IR, Johansen JD. Contact Allergy: A Review of Current Problems from a Clinical Perspective. Int J Environ Res Public Health. 2018 May 29;15(6):1108. doi: 10.3390/ijerph15061108.

Ríos F, Lechuga M, Fernández-Serrano M, Fernández-Arteaga A. Aerobic biodegradation of amphoteric amine-oxide-based surfactants: Effect of molecular structure, initial surfactant concentration and pH. Chemosphere. 2017 Mar;171:324-331. doi: 10.1016/j.chemosphere.2016.12.070.

Liao LL, Mo S, Lei JL, Luo HQ, Li NB. Application of a cosmetic additive as an eco-friendly inhibitor for mild steel corrosion in HCl solution. J Colloid Interface Sci. 2016 Jul 15;474:68-77. doi: 10.1016/j.jcis.2016.04.015.

References_________________________________________________________________________

(1) Cosmetic Ingredient Review Expert Panel. Amended final report of the safety assessment of cocamidopropylamine oxide. Int J Toxicol. 2008;27 Suppl 1:55-62. doi: 10.1080/10915810802032396. 

(2) Aerts O, van Dyck F, van Tichelen W, Lambert J. The many faces of coconut oil derivatives: occupational hand dermatitis caused by a liquid soap containing cocamidopropylamine oxide. Contact Dermatitis. 2016 Apr;74(4):248-51. doi: 10.1111/cod.12498.